Home Range and Movement Pattern of a Tailless Black Eagle in Taiwan: A Special Case of Noninvasive Study by Community Science

A secretive and cautious raptor, the Black Eagle (Ictinaetus malaiensis) is challenging to study. Its highly specialized foraging behavior makes it difficult to capture an individual for tracking. However, a tailless eagle provided an opportunity to describe the home range and movements of one bird for 3 yr from 2013 to 2016. A total of 43 independent photo records were provided by a bird photographers' community. The eagle regularly moved between summering and wintering habitats north and south of Taipei City, Taiwan; home range sizes were estimated as 54.1 and 47.1 km2, respectively. This noninvasive case study provides the first estimates of home range size and movement patterns for the Black Eagle, and highlights the contribution of community science to research on endangered raptors.